With the progress of telecommunication and information technology (IT) services, charging methods become flexible and diversified. All kinds of charging systems are widely used in telecommunication and IT services. In the traditional charging mode of an operator, online charging and control are implemented for prepaid users in real time through the intelligent network (IN), and the Business Operation Support System (BOSS) or hot billing system is adopted to perform offline charging for postpaid users. Online charging is a charging mechanism in which charging information may impact the provisioning of services, and the account balance is updated in real time. Therefore, in online charging, the charging process is part of the service flow and the charging mechanism interacts with session/service control directly. Offline charging is a charging mechanism in which charging information does not impact the provisioning of services in real time. Offline charging is a traditional “use before charging” method. After a user finishes using a service, the user is charged according to the generated call detail record (CDR).
FIG. 1 shows the structure of a charging system in the related art.
In the charging system, offline charging is implemented by a hot billing system. Hot billing is a type of offline charging. After obtaining the CDR in the online mode, the hot billing system charges the user immediately to minimize the time difference between service use and charging. As shown in FIG. 1, a hot billing system 112 collects CDRs from a Mobile Switching Centre (MSC) 111 in the circuit switched (CS) domain 11, Charging Gateway (CG) 123 in the packet switched (PS) domain 12, and Mobile Data Service Management Platform (MDSP) 131 in the service layer 13, and then charges users.
In the charging system, online charging is implemented by a hot billing system. The hot billing system in FIG. 1 includes a Service Control Point (SCP) 113 and a MDSP 131. The online charging for CS services is implemented by an IN. A Mobile Switching Centre/Service Switching Point (MSC/SSP) 111 is connected to the SCP 113, where account information of all users requiring online charging is stored, which enables billing for voice and point-to-point short message services in real time. The charging for bearer traffic in the PS domain 12 is implemented through an interface between the Serving GPRS Supporting Node (SGSN) 121 and the SCP 113; for content charging, the MDSP 131 completes ratings and interfaces with the SCP 113 to make real-time reservations and deductions.
The offline charging method based on the charging system in FIG. 1 includes the following steps:
1. A user uses a CS or PS domain service;
2. After the user finishes using the service, a related device (MSC in the CS domain, CG in the PS domain, or MDSP) generates a CDR;
3. The hot billing system collects the CDR from the related device (MSC in the CS domain, CG in the PS domain, or MDSP);
4. The hot billing system charges the user and performs appropriate actions on the user account.
The online charging method based on the charging system in FIG. 1 includes the following steps:
1. A user uses a CS or PS domain service;
2. When the use is using the service, a related device (MSC in the CS domain, SGSN/SSP in the PS domain or MDSP) interacts with the SCP in real time: in the case of a MSC or SGSN/SSP, the MSC or SGSN/SSP reports the usage information (such as traffic volume and duration) in real time and the SCP performs ratings, deductions and reservations; in the case of a MDSP, the MDSP rates the contents according to the usage information and requests the SCP to make deductions;
3. After the user finishes using the service, the related device (MSC in the CS domain, SGSN/SSP in the PS domain or MDSP) reports usage information to the SCP (the MDSP reports charges directly), and the SCP makes deductions and returns a deduction acknowledgement message to the related device.
In the charging system in FIG. 1, the SCP is on the network side and completes service control, so it must be reliable and stable; the charging function is implemented by the BOSS and requires high flexibility. The flexibility of the charging function requires frequent upgrades of the SCP, which will impact the reliability and stability of the SCP. Moreover, because pre-payment and post-payment are implemented in the IN and hot billing system, respectively, and the rating points of prepaid data and prepaid voices are different, it is hard to implement the switch between the prepaid and postpaid modes. In addition, for the voice domain, rating and charging are implemented in an IN; but for the data domain, rating and charging are implemented by the MDSP and deductions are made in the IN. Hence, it is hard to bind voice and data services, and the flexibility of service prices is not enough.
FIG. 2 shows the structure of another charging system in the related art. In the charging system in FIG. 2, the hot billing system 112 processes all billing actions uniformly. The component is single and the construction cost is low. But the billing actions are not real-time and the deduction period is long, so it is impossible to enable real-time service control. The SCP 113 and MDSP 131 no longer belong to the hot billing system, and between them, there is no deduction interface.
The offline charging method based on the charging system in FIG. 2 includes the following steps:
1. A user uses a CS or PS domain service;
2. After the user finishes using the service, a related device (MSC in the CS domain, CG in the PS domain, or MDSP) generates a CDR;
3. The hot billing system collects the CDR from the related device (MSC in the CS domain, CG in the PS domain, or MDSP);
4. The hot billing system charges the user and performs appropriate actions on the user account.
To avoid impacts on the processing performance of a service network, in this mode, CDRs are not collected at a high frequency. In addition, the processing in the hot billing system takes some time, resulting in a certain charging delay. Because the hot billing system processes the balance only after the conversation is over and the CDR is generated, it is impossible to realize a real-time service control. The risk of arrearage is high.